Hi i am hosting a bukkit server for my irl friends (only noone from riftland is allowed bc of i dont want to look like im trying to start another server no this is only part time for me and my friends trolling)

anywho i have portforwarded wiht 25565 and we have also tried hamachi. they can all join but after 5 min they all get disconnected for no reason. then i reboot the server and all works fine, for 5 mins -.- any idea what i can do to fix this its not my firewall we have tried without it being on. and its not their since 5 different people are having the same problem. I need your help since the ones with a computer that would be able to host (mine should do fine but for some stupid reason i caaant!) they have about 0 knowledge what so ever concerning installing usefull bukkit plugins. any idea why they get disconnected? i need this help since i am the only one of my friends who know anything about minecraft servers and i dont want to hold classes for them. Plox help O.O

_________________We must bring Rift/craftland Back! Kill all enemy servers, then a new round will start and we will respawn